1. Earth’s Changing Atmosphere
The sun supplies the atmosphere’s energy

2. Energy from the sun heats the atmosphere
Most energy comes from the Sun
Some of this energy takes the form of visible light
Radiation is energy that moves across distances in the form of electromagnetic waves (EM waves)
About 30% of incoming solar energy is reflected by clouds, the atmosphere, and Earth’s surface
About 70% of solar radiation is absorbed and becomes different forms of energy

3. The atmosphere moves energy
Energy moves place to place by radiation, conduction and convection
Earth’s surface, heated by the Sun, radiates energy that is absorbed by certain atmospheric gases, which then warms the air.
1. Conduction: the transfer of energy from one substance to another through direct contact
2. Convection: the transfer of energy from place to place by the motion of heated gas or liquid.
3. Radiation: energy that moves across distances

4. 6.2
Energy from the Sun moves through Earth's atmosphere in three ways.
Transfer of Energy
Radiation, conduction, and convection move energy from place to place.

7. The atmosphere has temperature layers
The atmosphere’s temperature changes with altitude
Starting from the Earth’s surface, the layers are:
1. Troposphere: temperatures decrease with altitude
2. Stratosphere: temperatures increase due to the presence of ozone (a gas that absorbs UV radiation)
3. Mesosphere: temperatures again decrease with altitude
4. Thermosphere: temperatures rise

9. Summarizing key points
3 – 2 – 1 3 Important facts 2 Questions you have 1 Main idea